快

Phono-semantic compound consisting of:

忄 (heart radical, from 心 “mind, emotion”) — indicates feelings and internal states.

夬 (guài) — suggesting both sound and the idea of decisiveness or cutting through swiftly.

Thus, 快 literally represents a state where the heart feels open, unblocked, or flowing freely — hence the meanings pleasant, satisfied, swift.

愉快 (유쾌) — pleasant, joyful

痛快 (통쾌) — thrilling, exhilarating

爽快 (상쾌) — refreshing, brisk

快樂 (쾌락) — pleasure, happiness

快速 (쾌속) — rapid, high-speed

快捷 (쾌결) — fast, efficient

快感 (쾌감) — pleasant sensation, gratification

快晴 (쾌청) — clear and pleasant weather

快諾 (쾌낙) — prompt consent or agreement

In Confucian and Daoist texts, 快 often transcends its ordinary sense of pleasure or speed.

It denotes a state of inner clarity and freedom — when the heart-mind (心) is open, balanced, and without resentment.

心快則明，心明則通。

“When the heart is at ease, it becomes clear; when clear, it perceives the Way.”

— Confucian aphorism, later echoed in Neo-Confucian commentaries.

Here 快 implies spiritual ease rather than sensual enjoyment.

An untroubled heart (快心) allows 明 (clarity) and 通 (communication with the Dao).

The opposite is 鬱 (울, depressed, blocked) — the stagnation of the heart’s energy.

In Daoist literature, 快 describes freedom from constraint:

聖人之心，虛而快，應萬物而不累。

“The sage’s heart is empty and free; it responds to all things without being burdened.” — Zhuangzi, ch. 7 (“應帝王”)

Thus 快 symbolizes flowing harmony (順) — the ease of being in accord with nature.

In later Confucian moral discourse:

Neo-Confucian writers like Zhu Xi (朱熹) and Wang Yangming (王陽明) used 快心 (“joy of the heart”) to describe the serenity of ethical satisfaction — the calm delight arising from virtue rather than indulgence.

義之快，非樂之快也。

“The joy of righteousness is not the joy of pleasure.”

Here 快 contrasts ethical joy (義快) with hedonic pleasure (樂快).